The broad objective of this program is the understanding of metabolic regulation. The specific goals in the development of this program fall in three categories: (a) the understanding of molecular interactions at the purified protein level (b) the understanding of controls in a model regulatory system, in particular the chemotactic sensory system of bacteria and (c) the understanding of the role of the opiate receptor in the pain mechanisms of higher species. The work will involve the study of purified proteins from each of these systems, the modification of these proteins with reporter groups such as fluorescent dyes, and the study of these proteins in partially or completely reconstituted systems. It is hoped that purification of the components and their modification of their in vivo interactions will lead to greater clarification of regulatory controls in general and feedback systems in particular.